JP6323319B2 - Illumination device and driving method thereof - Google Patents

Description

  The present invention relates to a lighting device and a driving method thereof.

  In recent years, there has been a strong demand for energy saving and mercury-free as an environmental measure, and a shift to a lighting apparatus using a light emitting diode (hereinafter also referred to as “LED”) is progressing. White light emitting devices using LEDs include light emitting devices that combine blue LEDs, green phosphors, and red phosphors. This light-emitting device is a so-called three-wavelength light-emitting device, and emits white light by mixing three colors of light. By using this light emitting device as a backlight of a liquid crystal display, an image display device having a wide color display range can be obtained. In addition, energy efficiency can be achieved because of high energy use efficiency. Furthermore, by using it as an illuminating lamp, a luminaire having a high luminous flux and a good color rendering property can be obtained.

In order to realize such a three-wavelength light emitting device, it has been proposed to use a phosphor using Mn ⁴⁺ as an activator (see, for example, Patent Document 1). As a result, the half-value width of the peak emitted in the red wavelength region is narrowed. As a result, an image display device having a wide color display range and an illumination lamp with high color rendering properties can be obtained.

By the way, afterglow time is mentioned as an example of characteristic evaluation of a fluorescent substance. For example, a fluoride phosphor activated with Mn ⁴⁺ (for example, the composition formula is represented by K ₂ Si ₂ F ₆ : Mn ⁴⁺ . Hereinafter, it may be referred to as “KSF phosphor”). , Eu-activated β sialon phosphor (for example, the composition formula is Si _6-Z Al _Z O _Z N _8-Z : Eu (0 <Z <4.2). Hereinafter, “β sialon phosphor” FIG. 14 shows changes in intensity from the start of irradiation with excitation light until the emission intensity reaches the maximum.

  As shown in FIG. 14, the β sialon phosphor reaches its maximum emission intensity 0.5 ms after excitation, whereas the KSF phosphor reaches its maximum at 24 ms. In addition, the KSF phosphor easily causes a phenomenon called afterglow after the excitation light irradiation is stopped, and the time until the light emission stops is longer than that of other phosphors. FIG. 15 shows the change in emission intensity after stopping the irradiation of excitation light for the KSF phosphor and the β sialon phosphor.

As shown in FIG. 15, the β sialon phosphor attenuates the emission intensity to 1/10 or less of the maximum value in about 0.2 ms after stopping the excitation light, but the emission intensity of the KSF phosphor is 1 / maximum of the maximum value. It takes about 20 ms to attenuate to 10. As a cause of such a phenomenon, there is generally a slow response to the excitation light of a phosphor activated with Mn ⁴⁺ .

JP 2010-93132 A

  Thus, there is a concern that, when a phosphor with a slow response is used, for example, when the light emission intensity of the LED is dimmed by pulse width modulation, the emission color changes compared to the case where the light intensity is not dimmed.

  The present invention has been made in view of the above problems, and one of its purposes is to prevent the emission color from changing when the light emission intensity is dimmed under different driving conditions as compared with the case where the light is not dimmed. An illumination device and a driving method thereof are provided.

According to one aspect of the present invention to solve the above-described problem, a first light emitting unit including a first light emitting element and a first phosphor that converts light emitted from the first light emitting element into light of a different wavelength; A second light emitting unit including a second light emitting element is electrically connected to the first light emitting unit and the second light emitting unit, respectively, and the first driving energy is supplied to the first light emitting element and the second light emitting element is supplied to the second light emitting element. The power supply unit that supplies drive energy, the first drive energy supplied from the power supply unit to the first light emitting unit, and the second drive energy supplied from the power supply unit to the second light emitting unit can be individually controlled. A control unit, and the first light emitting unit and the second light emitting unit measure the light emission intensities of the first light emitting unit and the second light emitting unit while changing driving conditions including lighting time. Standardized the light emission intensity of the first light emitting part with the light emission intensity of the two light emitting parts. If the driving time is shorter, the emission intensity of the first light emitting unit tends to increase, and the control unit is configured such that the integrated value of the first driving energy is greater than the integrated value of the second driving energy. The second light-emitting unit includes a second phosphor that converts light emitted from the second light-emitting element into light of a different wavelength, and the first phosphor is the decay time is Ru long red phosphor der than the second phosphor.

According to an aspect of the present invention, the integrated value of the first driving energy supplied to the first light emitting unit including the first phosphor having a different response than the second light emitting unit is smaller than the second driving energy. By controlling it, it is possible to realize an illumination device that maintains a balance of emission colors. Moreover, the illuminating device which maintained the balance of emitted light color is realizable by reducing the integration energy to the 1st light emission part containing the 1st fluorescent substance from which responsiveness differs from 2nd fluorescent substance.

It is a block diagram which shows the illuminating device which concerns on Embodiment 1 of this invention. 3 is a schematic cross-sectional view showing a first light emitting unit and a second light emitting unit according to Embodiment 1. FIG. It is a schematic plan view which shows a surface mount type light emission part. It is a schematic cross section in the "IV-IV" line of the light emission part of FIG. 6 is a schematic cross-sectional view showing a light emitting unit according to Embodiment 2. FIG. 6 is a schematic cross-sectional view showing a light emitting unit according to Embodiment 3. FIG. 6 is a schematic cross-sectional view showing a light emitting unit according to Embodiment 4. FIG. 6 is a schematic cross-sectional view showing a light emitting unit according to Embodiment 5. FIG. It is a schematic cross section which shows the light emission part which concerns on the comparative example 1 shown for a comparison with this invention. It is the graph which measured the spectral distribution of the output light for 50 ms which driven the illuminating device concerning the comparative example 1 shown for a comparison with this invention with direct current. It is a graph which shows a mode that the emitted light intensity of red light changes on different drive conditions. FIG. 12A is a graph showing the time change of current during DC driving, and FIG. 12B is a pulse driving. It is the graph which measured the spectral distribution of the output light for 50 ms which driven the illuminating device concerning Example 1 by direct current. It is a graph which shows the change of the emitted light intensity after starting irradiation of excitation light about KSF fluorescent substance and beta sialon fluorescent substance. It is a figure which shows the change of the emitted light intensity after stopping irradiation of excitation light about KSF fluorescent substance and (beta) sialon fluorescent substance.

  Hereinafter, an embodiment of the present invention will be described with reference to the drawings as appropriate. However, the illuminating device described below is for embodying the technical idea of the present invention, and unless otherwise specified, the present invention is not limited to the following. The contents described in one embodiment and example are applicable to other embodiments and examples. The size and positional relationship of the members shown in each drawing may be exaggerated for clarity of explanation.

According to the lighting device according to an embodiment of the present invention, a first light emitting unit including a first light emitting element and a first phosphor that converts light emitted from the first light emitting element into light of a different wavelength; A second light emitting unit including a second light emitting element is electrically connected to the first light emitting unit and the second light emitting unit, respectively, and the first driving energy is supplied to the first light emitting element and the second light emitting element is supplied to the second light emitting element. The first drive energy and the second drive supplied by the power supply unit so as to drive the first light emitting unit and the second light emitting unit, respectively, connected to the power supply unit that supplies driving energy and the power supply unit, respectively. A control unit for sending control information for controlling the amount of energy to the power supply unit, and the control unit changes a driving condition including a lighting time of the first light emitting unit or the second light emitting unit. The first light emission before and after the change of the driving condition To keep the emission intensity ratio of the second light-emitting portion with respect to the constant, the and controls the first driving energy or the second drive energy, the second light emitting unit, the second light emitting element having a different wavelength of light emitted by the A second phosphor that converts light may be included, and the first phosphor may be a red phosphor that has a longer afterglow time than the second phosphor . With the above configuration, it is possible to realize an illuminating device that maintains a balance of emission colors by reducing the energy accumulated in the first light emitting unit including the first phosphor having a different responsiveness than the second phosphor.

  According to another illumination device, the driving condition can be a duty ratio in the pulse width modulation method.

  Furthermore, according to another illuminating device, Eu-activated β sialon phosphor can be included as the second phosphor.

Furthermore, according to another illumination device, the first phosphor, the composition formula is _{3.5MgO · 0.5MgF 2 · GeO 2:} Mn is represented by Mn ^{4+ 4+} -activated Mg fluoro jar money DOO Phosphor or composition formula is M ¹ ₂ M ² F ₆ : Mn ⁴⁺ (where M ¹ is at least one selected from Li ⁺ , Na ⁺ , K ⁺ , Rb ⁺ , Cs ⁺ , NH ⁴⁺⁾ , M ² is at least one selected from Si, Ge, Sn, Ti, and Zr.) And can contain a Mn ⁴⁺ activated fluoride phosphor.

Still further, according to another illumination device, further comprising a storage unit for storing a change amount of the emission intensity of the first light-emitting unit and the second light-emitting unit, which changes according to the driving time, control unit refers to the SL 憶 portion such that said emission intensity of the first light emitting portion becomes constant, according to the drive time of the first light emitting portion or the second light emitting portion, the first driving energy The integrated value or the integrated value of the second driving energy can be adjusted.

Furthermore, according to another lighting device, when the light emission intensity of the first light emitting unit increases as compared with the second light emitting unit as the driving time is shorter, the control unit is compared with the second light emitting unit. Thus, the integrated value of the first driving energy supplied to the first light emitting unit can be controlled so as to cancel out the increase that increases.

Furthermore, according to another lighting device, when the light emission intensity of the first light emitting unit increases as compared with the second light emitting unit as the driving time is shorter, the control unit is compared with the second light emitting unit. And controlling to increase the integrated value of the second driving energy supplied to the second light emitting unit whose light emission intensity is lower than that of the first light emitting unit so that the increased increase is offset. Can do.

  Furthermore, according to another illumination device, the control unit drives the first light emitting element and the second light emitting element by a pulse width modulation method, and the pulse width for driving the first light emitting element is set as follows: It can be controlled to be narrower than the pulse width for driving the second light emitting element. With the above configuration, by adjusting the integrated amount of energy supplied to the light emitting element driven by the PWM method, it is possible to suppress a situation where the light emission intensity of the first light emitting unit to the second light emitting unit becomes strong when the drive pulse width is short. Thus, it becomes possible to maintain the balance of the emission colors.

  Furthermore, according to another illumination device, the second light emitting unit further includes, as a third phosphor, an Eu-activated chlorosilicate phosphor, an Eu-activated silicate phosphor, an Eu-activated thiogallate phosphor, a rare earth aluminate One or more of the salt phosphors can be included.

  Furthermore, according to another illumination device, the first light emitting element and the second light emitting element can be blue light emitting diodes.

  Furthermore, according to another illumination device, the first light emitting unit may include a first phosphor, and the second light emitting unit may include the first phosphor in addition to the second phosphor.

  Furthermore, according to another illumination device, the first light emitting unit and the second light emitting unit can be formed in the same package.

  Furthermore, according to another illuminating device, the said control part can be equipped with the light control function of output light.

Furthermore, according to the driving method of the illumination device, a first light emitting unit including a first light emitting element, a first phosphor that converts light emitted from the first light emitting element into light of a different wavelength, and a second light emission. A second light emitting unit including an element, and the first light emitting unit and the second light emitting unit are electrically connected to each other, and the first driving energy is supplied to the first light emitting element, and the second driving energy is supplied to the second light emitting element. , A power supply unit to be supplied, and a control unit connected to the power supply unit for sending control information for controlling the amount of the first drive energy and the second drive energy supplied by the power supply unit to the power supply unit A method of driving an illumination device comprising: a step of causing the first light emitting unit and the second light emitting unit to emit light under different driving conditions and measuring light emission intensity under each driving condition; For one light emitting part A step of calculating a first drive energy or an integrated value of the second drive energy that keeps a light emission speed ratio of the second light emitting unit constant, and the calculated integrated value of the first drive energy or the second drive energy, look including the step of supplying the first emitting section or the second light emitting portion, wherein the first phosphor having a composition _{formula, 3.5MgO · 0.5MgF 2 · GeO 2} : Mn 4 represented by Mn ^{4+ +} Activated Mg fluorogermanate phosphor, or composition formula M ¹ ₂ M ² F ₆ : Mn ⁴⁺ (where M ¹ is Li ⁺ , Na ⁺ , K ⁺ , Rb ⁺ , Cs ⁺ , NH ⁴ at least one selected from ^+, M ² is free Si, Ge, Sn, Ti, and Mn ⁴⁺ -activated fluoride phosphor represented by at least one selected from Zr.) You can

Furthermore, according to another driving method of a lighting device, a first light emitting unit including a first light emitting element and a first phosphor that converts light emitted from the first light emitting element into light of a different wavelength, A second light-emitting unit including two light-emitting elements, and the first light-emitting part and the second light-emitting part are electrically connected to each other, the first drive energy is supplied to the first light-emitting element, and the second drive is supplied to the second light-emitting element. A power supply unit that supplies energy, and control information that is connected to the power supply unit and controls the amount of the first drive energy and the second drive energy supplied by the power supply unit to the power supply unit A control unit, wherein the first light-emitting unit and the second light-emitting unit measure the light emission intensities of the first light-emitting unit and the second light-emitting unit while changing driving conditions including lighting time. Emission intensity of the first light emitting part is standardized by the emission intensity of the two light emitting parts In this case, the driving method of the lighting device shows a tendency that the light emission intensity of the first light emitting unit increases as the driving time is shorter, and the control unit emits light from the first light emitting unit as the driving time is shorter. Determining a correction amount for correcting an integrated value of driving energy supplied to the first light emitting element so as to cancel out an increase in intensity compared to the second light emitting unit; and , together with driving the second light emitting element in the second drive energy, to said first light emitting element, seen including a step of driving with a corrected according to the correction amount the determined the first drive energy, said first one phosphor having a composition _{formula, 3.5MgO · 0.5MgF 2 · GeO 2} : Mn 4+ -activated Mg fluoro jar money preparative phosphor represented by Mn ^4+, or composition formula M ¹ ₂ M ² F _6: Mn ⁴⁺ (where, M ¹ is, L ^{+, Na +, K +,} Rb +, Cs +, at least one selected from NH ^4+, M ² is at least one selected Si, Ge, Sn, Ti, from Zr. the Mn ⁴⁺ -activated fluoride phosphor represented by) may contains Mukoto.

The configuration of the lighting apparatus according to Embodiment 1 of the present invention is shown in the block diagram of FIG. The lighting device 100 shown in this figure includes a light emitting unit 1, a power supply unit 2, and a control unit 3. Hereinafter, the light emitting unit 1, the power supply unit 2, and the control unit 3 will be described.
(Light Emitting Unit 1)

  The structure of the light emitting unit 1 is shown in the schematic cross-sectional view of FIG. The light emitting unit 1 shown in this figure includes a first light emitting unit 10 and a second light emitting unit 20 that are individually configured. The first light emitting unit 10 includes a first light emitting element 11 and a first phosphor 12 that is optically coupled to the first light emitting element 11 and converts light emitted from the first light emitting element 11 into light of a different wavelength. Prepare.

  On the other hand, the second light emitting unit 20 includes a second light emitting element 21 and a second phosphor 22 that is optically coupled to the second light emitting element 21 and converts light emitted from the second light emitting element 21 into light of a different wavelength. Including. In this example, the first light emitting unit 10 and the second light emitting unit 20 can reduce the manufacturing cost as a substantially common specification except that the phosphors are different.

  Details of each light emitting unit will be described with reference to FIGS. 3 and 4. In this example, the configuration of a surface-mounted light-emitting device is adopted, FIG. 3 is a schematic plan view of a light-emitting portion, and FIG. 4 is a schematic cross-sectional view taken along the line “IV-IV” shown in FIG. This light emission part has shown the 1st light emission part 10 as an example. The first light emitting unit 10 includes a first package 13 having a first recess 14, a first light emitting element 11, and a sealing member 16 that covers the first light emitting element 11.

  The first light emitting element 11 is disposed on the bottom surface of the first recess 14 formed in the first package 13, and the pair of positive and negative lead electrodes 17, 18 disposed in the first package 13 is electrically connected by the conductive wire 19. Connected. The sealing member 16 is filled in the first recess 14 so as to cover the first light emitting element 11, and contains the second phosphor 12. The sealing member 16 functions as a wavelength conversion member while protecting the first light emitting element 11 and other members from the external environment. Further, one end of the pair of positive and negative lead electrodes 17 and 18 is exposed on the outer surface of the first package 13. The light emitting unit 100 emits light when power is supplied from outside through the lead electrodes 17 and 18.

  The first and second light emitting elements are a semiconductor laminate in which a first semiconductor layer (for example, an n-type semiconductor layer), a light emitting layer, and a second semiconductor layer (for example, a p-type semiconductor layer) are stacked in this order. In addition, electrodes connected to the first semiconductor layer and the second semiconductor layer are provided.

The kind and material of the semiconductor are not particularly limited, and examples thereof include various semiconductors such as III-V compound semiconductors and II-VI compound semiconductors. Specific examples include nitride semiconductor materials such as In _X Al _Y Ga _1-XY N (0 ≦ X, 0 ≦ Y, X + Y ≦ 1), and include InN, AlN, GaN, InGaN, AlGaN, and InGaAlN. Etc. can be used. As the film thickness and layer structure of each layer, those known in the art can be used. Since the size and shape of the light emitting element and the phosphor are excited, the emission wavelength can be selected as appropriate.

  As the phosphors included in the light emitting unit, a first phosphor 12 included in the first light emitting unit 10 and a second phosphor 22 included in the second light emitting unit 20 are provided. Here, the first phosphor 12 is a phosphor having a longer afterglow time than the second phosphor 22. By doing in this way, the integrated energy to the 1st light emission part 10 containing the 1st fluorescent substance 12 from which the response characteristic differs from the 2nd fluorescent substance 22 is reduced relatively, and the illuminating device which maintained the balance of emitted light color (Details will be described later).

As the first phosphor 12, a red phosphor that is excited by light emitted from the first light emitting element 11 and emits red fluorescence is used. Such a first phosphor 12 includes a phosphor activated with tetravalent manganese ions, for example, Mn whose composition formula is represented by 3.5MgO.0.5MgF ₂ .GeO ₂ : Mn ^{4+. 4 +} -activated Mg fluorogermanate phosphor, and the composition formula is M ¹ ₂ M ² F ₆ : Mn ⁴⁺ (M ¹ is Li ⁺ , Na ⁺ , K ⁺ , Rb ⁺ , Cs ⁺ , NH ⁴⁺ And M ² is at least one selected from Si, Ge, Sn, Ti, and Zr.) Mn ⁴⁺ activated fluoride phosphor (KSF fluorescence) Body) is a preferred specific example.

As the second phosphor 22, green light emission that is excited by light emitted from the second light emitting element 21 and emits green fluorescence is used. An Eu-activated β sialon phosphor is used as the second phosphor 22 that emits green light. Thereby, a green phosphor with good responsiveness can be formed. As the phosphor of this embodiment, KSF phosphor emitting red light is, K ₂ SiF ₆ is activated phosphors with Mn ^4+: using Mn ^4+. A β sialon phosphor is used as the phosphor emitting green light. Thereby, a green phosphor with good responsiveness can be formed.

The phosphor is not limited to being contained in the sealing member, and can be provided in various positions and members of the light emitting unit. For example, it may be provided as a wavelength conversion member that is applied and bonded onto a sealing member that does not contain a phosphor.
(Power supply unit 2)

The power supply unit 2 is electrically connected to the first light emitting unit 10 and the second light emitting unit 20, respectively. The power supply unit 2 supplies the first driving energy to the first light emitting element 11 and the second driving energy to the second light emitting element 21.
(Control unit 3)

  The control unit 3 is connected to the power supply unit 2. The control unit 3 can individually control lighting of the first light emitting unit 10 and the second light emitting unit 20. Specifically, the amount of the first driving energy supplied from the power supply unit 2 to the first light emitting element 11 and the amount of the second driving energy supplied to the second light emitting element 21 can be controlled independently.

  Moreover, the control part 3 is equipped with the light control function which adjusts the brightness of the output light of an illuminating device. Specifically, the brightness is changed by adjusting the driving energy supplied to each light emitting element. For example, PWM control is performed to change the pulse width of the current for driving the light emitting element. For such a control unit 3, an LED driver or a computer having a dimming function can be used.

Furthermore, when the drive part including the lighting time of the 1st light emission part 10 or the 2nd light emission part 20 is changed, the control part 3 light emission of the 2nd light emission part 20 with respect to the 1st light emission part 10 before and behind the change of a drive condition. The first drive energy or the second drive energy is controlled so as to keep the intensity ratio constant.
(Storage unit 4)

The lighting device may be provided with a storage unit 4. The storage unit 4 is connected to the control unit 3. The storage unit 4 holds control information that is the basis of control of the control unit 3. Specifically, the amount of change in which the light emission intensity of the first light emitting unit 10 and the second light emitting unit 20 changes in accordance with the driving energy supplied to the light emitting unit 1, for example, the pulse width of the driving current, is measured in advance. (Details will be described later). As the storage unit 4, a non-volatile memory such as E ² PROM is preferably used.
[Embodiment 2]

  In addition to the first phosphor 12 and the second phosphor 22, other phosphors can be appropriately added to the first light emitting unit 10 and the second light emitting unit 20. For example, like the light emitting unit 1B according to Embodiment 2 shown in FIG. 5, the third phosphor 25 may be added to the second light emitting unit 20B. The third phosphor 25 can include, for example, one or more of Eu-activated chlorosilicate phosphor, Eu-activated silicate phosphor, Eu-activated thiogallate phosphor, and rare earth aluminate phosphor. The second phosphor 22B, the first light emitting element 11B of the first light emitting unit 10B, the first phosphor 12B, and the like can be the same as in the first embodiment. Also, the first package 13B and the first recess 14B of the first light emitting unit 10B and the second package 23B, the second recess 24B, the second light emitting element 21B, the second phosphor 22B, etc. of the second light emitting unit 20B are implemented. This can be the same as in the first mode.

Alternatively, the second phosphor may be mixed with the first phosphor in addition to the second phosphor. Thus, by disperse | distributing and arrange | positioning a 1st fluorescent substance in a 1st light emission part and a 2nd light emission part, the chromaticity difference of a 1st light emission part and a 2nd light emission part does not stand out.
[Embodiment 3]

Or conversely, as in the light emitting unit 1C according to Embodiment 3 shown in FIG. 6, the second light emitting unit 20C may be configured not to include a phosphor. In particular, when the second phosphor has an excellent response speed, the second light emitting element and the second phosphor can be identified with each other. Therefore, it may be handled without considering the presence or absence of the second phosphor, and in the present specification, the second light-emitting portion not including the second phosphor is also an object. In the example of FIG. 6 as well, the first package 13C and the first recess 14C of the first light emitting unit 10C, the first light emitting element 11C, the first phosphor 12C, and the second package 23C of the second light emitting unit 20C, the second The recess 24C, the second light emitting element 21C, and the like can be the same as those in the first embodiment described above.
[Embodiment 4]

In addition, the package which accommodates a light emitting element and fluorescent substance is set as the structure provided separately by the 1st light emission part 10 and the 2nd light emission part 20 as shown in FIG. 2, and the light emission which concerns on Embodiment 4 shown in FIG. It is good also as a common package 13D like the part 1D. In this example, the first light emitting element 11D that constitutes the first light emitting part, the first recess 14D that is the first light emitting area that accommodates the first phosphor 12D, and the second light emitting element 21D that constitutes the second light emitting part. A second recess 24D, which is a second light emitting region for accommodating the second phosphor 22D, is provided individually in the common package 13D. With such a configuration, the lighting device can be reduced in size, simplified in configuration, and reduced in cost.
[Embodiment 5]

  Or it is good also as a structure which makes a recessed part common and fills a common recessed part with a 1st light emitting element and 1st fluorescent substance and a 2nd light emitting element and 2nd fluorescent substance. Such an example is shown in the cross-sectional view of FIG. 8 as the light emitting unit 1E according to the fifth embodiment. In the light emitting unit 1E shown in this figure, a common recess 14E provided in the common package 13E is filled with the first light emitting element 11E and the first phosphor 12E, and the second light emitting element 21E and the second phosphor 22E. Thus, further downsizing and common use of members can be achieved.

  In either case, the afterglow characteristics of the first light emitting unit and the second light emitting unit are different when viewed as a light emitter including a phosphor. In particular, some phosphors have different afterglow characteristics. In this case, the phosphor having a long afterglow characteristic emits fluorescence even after the light emitting element as the excitation source is turned off, and therefore the emission color, that is, the color of the light emitting portion differs depending on the remaining fluorescence. Therefore, in consideration of such a difference in afterglow characteristics, control is performed in advance to adjust the light emission amounts of the first light emitting unit and the second light emitting unit in consideration of the remaining fluorescent component. Thereby, it is possible to realize a high-quality lighting device that maintains a constant color balance. Specifically, when the afterglow of the first light emitting unit is longer than that of the second light emitting unit, the light emission amount of the first light emitting unit is suppressed, the light emission amount of the second light emitting unit is added, or both Control is performed so that the relative light emission amount is maintained at the desired color balance. This control is performed by the control unit 3.

In other words, when the first light emitting unit and the second light emitting unit emit light with the same driving time, the results of measuring the emission intensity of the first light emitting unit and the second light emitting unit while changing the driving time are When the light emission intensity of the first light emitting part is normalized by the light emission intensity of the light emitting part, the light emission intensity of the first light emitting part tends to increase as the driving time is shorter. Therefore, the control unit 3 performs control so that the integrated value of the first driving energy is relatively lower than the integrated value of the second driving energy. In this way, the control unit 3 performs control so that the integrated value of the first driving energy supplied to the first light emitting unit including the first phosphor 12 having a response characteristic different from that of the second light emitting unit is smaller than the second driving energy. By doing so, it is possible to realize an illuminating device that maintains a balance of emission colors.
[Comparative Example 1]

Next, as a lighting device according to Comparative Example 1, a light emitting unit shown in FIG. 9 was created, and its spectrum was measured. Here, the light emitting element 91 is mounted as a common excitation light source in one package 93, and the wavelength conversion member formed by mixing the first phosphor 92 and the second phosphor 95 in the resin is filled in the recess 94. Thus, the lighting device 90 was produced. As the light emitting element 91, a blue light emitting diode (LED) having a maximum light emitting wavelength (peak wavelength) of 447 nm was used. As the first phosphor 92, a KSF phosphor having a composition formula of K ₂ SiF ₆ : Mn ⁴⁺ as a red phosphor was prepared. Further as the second phosphor 92, a green phosphor in which a composition formula _{Si 6-Z Al Z O Z} N 8-Z: was prepared Eu beta SiAlON phosphor represented by (0 <Z <4.2). In order to encapsulate the light emitting element 91, the first phosphor 92, and the second phosphor 95, a package 93 having a recess 94 formed of resin on a lead frame was prepared.
(DC drive)

  Here, the direct current is supplied to the light emitting element 91 from the power supply unit 2 and the spectral distribution of the output light for 50 ms is measured, and the graph of FIG. As shown in this figure, emission peaks indicating blue LED emission, β sialon phosphor fluorescence, and KSF phosphor fluorescence were observed in order from the short wavelength side.

  Next, the current supplied from the power supply unit 2 to the light emitting element 91 by the control unit 3 is switched from direct current drive to pulse drive, and the pulse width is changed, and among the obtained light emission, the emission intensity of red light is changed. The results normalized with blue light are shown in the graph of FIG.

Thus, in direct current drive, the light output at the peak wavelength of red light (633 nm) was 131 when the light output at the peak wavelength of blue light (441 nm) was 100.
(2.5nm pulse drive)

Next, the lighting device was turned on with the current supplied from the power supply unit 2 to the light emitting element 91 by the control unit 3 as a pulse current of 2.5 ms, and the spectrum of the output light obtained by leaving it for 50 ms was measured. Similarly to the above, when the light output at the peak wavelength of blue light (441 nm) is taken as 100, the light output at the peak wavelength of red light (633 nm) was calculated to be 139. Compared to the light output 131 in the case of the DC drive described above, it was 106%, and red light was excessive from the design value of the emission spectrum.
(0.5 nm pulse drive)

Further, the pulse current value was shortened, a pulse current of 0.5 ms was supplied, and the spectrum of the output light obtained by leaving it for 50 ms was measured. Similarly to the above, when the light output at the peak wavelength of blue light (441 nm) is taken as 100, the light output at the peak wavelength of red light (633 nm) is calculated to be 143. It was 109% compared with the light output 131 in the case of constant current, and red light was excessive from the design value of the emission spectrum.
[Example 1]

  As in the comparative example described above, when switching from direct current driving to pulse driving, the emission intensity of red light increases with respect to blue light, and as a result, the color balance is lost. In particular, when white light is to be obtained as illumination light, when switching from direct current drive to pulse drive, the red component becomes relatively large and the color changes. Therefore, the control unit 3 adjusts the balance between the red light and the blue light so as to be kept constant regardless of the time width of the drive current. Specifically, the first phosphor and the second phosphor are not used in common, and the first phosphor 12 that excites the first phosphor 12 and the second light-emitting element 21 that excites the second phosphor 22. And prepare separately. Further, the control unit 3 can turn on and drive the first light emitting element 11 and the second light emitting element 21 individually.

  In the present embodiment, the control unit 3 maintains a constant amount of current for driving the second light emitting element 21 for obtaining blue light and green light, while maintaining a constant amount of current for obtaining red light, that is, a red phosphor. The drive current amount of the first light emitting element 11 that excites a certain first phosphor 12 is adjusted. In other words, the control unit 3 adjusts the integrated value of the first driving energy according to the driving time of the second light emitting unit 20 so that the light emission intensity of the first light emitting unit 10 is constant. Here, the integrated value of the first drive energy is adjusted by changing the drive time of the current value (first drive current) for driving the first light emitting element, and the pulse width in the pulse drive. Specifically, in accordance with the pulse width of the driving current that drives the second light emitting element 21, the intensity of red light obtained by subtracting the increase amount of the red component in this pulse width is obtained from the intended pulse width. The first driving current shortened is supplied to the first light emitting element.

In performing the individual control of the first light emitting unit 10 and the second light emitting unit 20 by the control unit 3 as described above, it is necessary to grasp the change in the light emission intensity for each pulse width in advance. And in the state which hold | maintains such control information, at the time of an actual lighting drive, the control part 3 correct | amends the drive energy which should be lighted based on control information, and performs a lighting drive. Such control information includes a method of lighting an actually manufactured lighting device and storing measured data in the storage unit 4 as a lookup table, and a change in the emission intensity obtained by simulation. A method of storing the data in the storage unit 4 can be used. Or it is good also as a method of preparing a computing equation and calculating the variation | change_quantity of emitted light intensity for every pulse width. In this case, it is not necessary to prepare a storage unit for holding a lookup table or the like, and the hardware configuration can be simplified.
(Creation of lighting device control information)

  In order to control the lighting apparatus of the present embodiment, a procedure for creating control information will be described in advance.

  (1) First, as the first step, the first light emitting unit 10 emits light under different driving conditions, and the emission intensity before and after the change of the driving conditions is measured. Here, the different driving conditions include a DC driving method, a pulse width modulation method (including a case where the duty ratio is changed), and the like. Moreover, you may include the conditions which changed drive time, the voltage, and the electric current amount. Here, for each of the pulse drive in which the pulse time is changed from the DC drive, the light emission spectrum is measured by actually turning on the illumination device.

  (2) Next, as a second step, the light emission intensity obtained by normalizing the light emission amount of the first light emitting unit 10 by the second light emitting unit 20 is acquired for each driving condition, for example, for each pulse width of the driving current. As an example, the difference before and after the change of the driving condition may be calculated. Here, the driving condition on the second light emitting unit 20 side is fixed, and the difference in light emission intensity of the first light emitting unit 10 is calculated. This difference in emission intensity can be calculated, for example, as the difference in peak intensity of the emission spectrum shown in FIG.

  (3) Further, as a third step, a first driving energy or an integrated value of the second driving energy for maintaining a constant light emission speed ratio of the second light emitting unit 20 to the first light emitting unit 10 for each driving condition is calculated. For example, an integrated value of driving energy necessary for canceling the difference in light emission intensity calculated in the second step is calculated. Here, the “integrated value of driving energy” refers to the product of the current flowing through the light emitting element, the voltage applied to the light emitting element, and the driving time of the light emitting element. For example, the time-varying current amount shown in FIG. 12A or 12B refers to the product of the sum of the areas surrounded by the solid line and the voltage.

  Here, the control unit 3 calculates the correction amount of the driving energy necessary for canceling the difference in peak intensity of the emission spectrum obtained in the second step. Here, it is necessary to adjust the driving energy so that the peak heights are substantially equal, and to maintain a constant light emission intensity ratio of the second light emitting unit 20 to the first light emitting unit 10 before and after the change of the driving condition. The amount of change in drive energy is calculated. For example, the peak height of the light emission intensity is obtained by obtaining the peak height of the light emission intensity for each different driving condition (specifically, the PWM ON duty) and multiplying the integrated value of the drive energy by the change rate of the peak height. The drive energy with substantially the same length is calculated.

  (4) Finally, as the fourth step, each light emitting unit is driven based on the calculated drive energy correction amount. Specifically, the first light emitting unit 10 has a corrected integrated value of the first driving energy corrected based on the driving energy correction amount, while the second light emitting unit 20 has the second driving energy that has not been corrected. The control unit 3 controls the current value supplied from the power supply unit 2 to the first light emitting unit 10 and the second light emitting unit 20 so as to supply the integrated value.

  As described above, with the control information created in advance and stored in the storage unit 4, the control unit 3 refers to the control information for the lighting control information and calculates the drive energy correction amount during actual lighting. Each light emitting unit is controlled by the corrected drive energy. The drive energy correction amount does not necessarily have to be calculated, and a correction current value that takes the drive energy correction amount into consideration for each pulse width may be calculated in advance and stored in the storage unit 4 in advance as a lookup table. Good. In this case, the correction current value can be acquired simply by referring to the look-up table, so that the calculation work can be saved and the processing amount of the control unit 3 can be reduced.

  In the above example, the method of lighting control of each light emitting element by the PWM method has been described. However, the present invention does not limit the lighting driving method of the light emitting element to the PWM method, but other methods such as a PAM for adjusting the amplitude, a method for adjusting the driving energy by adjusting the number of pulses having a certain width, etc. A known lighting drive control method can be used as appropriate.

  In the above method, the method of reducing the lighting amount of the first light emitting element, that is, the integrated value of the first driving energy, is reduced from the integrated value of the second driving energy while maintaining the second driving energy. However, the present invention is not limited to this method. For example, the first drive energy side may be maintained and the integrated value on the second drive energy side may be controlled to be larger than the integrated value of the first drive energy. Or you may perform simultaneously the control which increases the integrated value of 1st drive energy, and reduces the integrated value of 2nd drive energy. In this way, by making the integrated value of the first driving energy relatively lower than the integrated value of the second driving energy, in the illumination device using a plurality of phosphors or light emitting elements having different afterglow characteristics, direct current driving is performed. Therefore, it is possible to suppress a change in the color balance when changing from time-to-time lighting to high-quality lighting.

Further, in the above example, the example in which the first light emitting unit and the second light emitting unit are used as the light emitting unit has been described. It is also possible to calculate a driving energy correction amount corresponding to the afterglow characteristics of each light emitting unit using the above and control so that the light emission intensity of each light emitting element does not change even under different driving conditions.
(Configuration of lighting device)

  Next, the configuration of the illumination device according to the first embodiment will be described. Here, as shown in FIG. 2, the first light emitting unit 10 and the second light emitting unit 20 are separated, and these can be individually driven by the control unit 3. The first light emitting unit 10 includes a first phosphor 12 and a first light emitting element 11 that excites the first phosphor 12. The second light emitting unit 20 includes a second phosphor 22 and a second light emitting element 21 that excites the second phosphor 22.

The first light-emitting element 11 and the second light-emitting element 21 used as excitation sources in the first light-emitting unit 10 and the second light-emitting unit 20 are blue light-emitting diodes having a maximum emission wavelength (peak wavelength) of 447 nm, as in the comparative example. LED) was prepared. As the first phosphor 12, the composition formula is a red phosphor K ₂ SiF _6: were prepared KSF phosphor is Mn ^4+. Further as the second phosphor 22, a green phosphor in which a composition formula _{Si 6-Z Al Z O Z} N 8-Z: was prepared Eu beta SiAlON phosphor represented by (0 <Z <4.2). These light emitting elements and phosphors are enclosed in the first recess 14 and the second recess 24 of the first package 13 and the second package 23 shown in FIG. I got each. Each phosphor is filled in a recess of a package on which a light emitting element is mounted as a wavelength conversion member formed by mixing in a resin.
(Control of lighting device)

  First, the spectral distribution during DC driving was measured as driving conditions. Here, the spectral distribution when a constant direct current is supplied to the first light-emitting element 11 and the second light-emitting element 12 individually mounted on the first package 13 and the second package 23 under the same conditions and measured for 50 ms. Is shown in FIG. The light output at the peak wavelength of red light (633 nm) when the light output at the peak wavelength of blue light (441 nm) is 100 was 131, and the same spectral distribution as in the comparative example was obtained.

  Next, as different driving conditions, a pulse current of 2.5 ms was supplied to each of the first light emitting unit 10, the first light emitting element 11 of the second light emitting unit 20, and the second light emitting element 12, and measurement was performed for 50 ms. Here, in order to adjust the light emission intensity of the second light emitting unit 20 to be relatively small, the control unit 3 performs current correction in consideration of the drive energy correction amount. Specifically, in order to correct the emission intensity of the KSF phosphor and keep the emission intensity ratio of the second light emitting unit 20 to the first light emitting unit 10 constant, the first light emitting element 11 combined with the β sialon phosphor. The amount of current supplied to the second light-emitting element 21 combined with the KSF phosphor was reduced to 94% with respect to the amount of current input to. That is, the energy density of red light (633 nm) during DC driving is 131 in terms of the blue light ratio, while the energy density of red light during 2.5 ms pulse driving is 139. It is calculated as 131 ÷ 139 = 94%. As a result, when the light output at the blue light peak wavelength (441 nm) is 100, the light output at the red light peak wavelength (633 nm) is 131, and the same spectral distribution as the light output at the time of DC driving is obtained. I was able to.

  Further, by changing the driving conditions, a pulse current of 0.5 ms is supplied to each of the first light emitting unit 10 and the first light emitting element 11 and the second light emitting element 12 of the second light emitting unit 20 so as to reduce the output light, Measurement was performed for 50 ms. Here, the control unit 3 reduces the amount of current supplied to the second light emitting element 21 to 92% of the amount of current input to the first light emitting element 11. In this calculation, as described above, the energy density of red light at the time of DC driving is 131, while the energy density of red light at the time of 0.5 ms pulse driving is 143. Therefore, the correction amount of the current amount is 131 ÷. It is calculated that 143 = 92%. As a result, when the light output at the peak wavelength (441 nm) of blue light is set to 100, the light output at the peak wavelength (633 nm) of red light is 131, and the same optical output spectral distribution as that at the time of DC driving is obtained. I was able to. Table 2 shows the measurement results of the emission intensity of these Examples 1.

  In this way, it is possible to keep the intensity ratio of red light and blue light constant regardless of the pulse width of the pulse current supplied to the light emitting unit, and thus the color balance before and after such changes in driving conditions. It is possible to obtain a high-quality illumination that is maintained. Such a change in the driving condition is particularly likely to occur during a change in illumination brightness, that is, during dimming. In the configuration as shown in FIG. 9, when the light emission intensity is dimmed by pulse width modulation, the light output of a phosphor having different afterglow characteristics, for example, a KSF phosphor, is increased as compared with the case where the light intensity is not dimmed. However, according to Example 1, it is possible to suppress such a change in emission color. That is, in the lighting device according to the first embodiment, the first wavelength conversion member including the KSF phosphor as the first phosphor 12 is enclosed in the first package 13 together with the first light emitting element 11 to form the first light emitting unit 10. On the other hand, the second wavelength conversion member including the β sialon phosphor as the second phosphor 22 is enclosed in the individual second package 23 together with the second light emitting element 21 to form the second light emitting unit 20. These light emitting units can be individually controlled.

  The control unit 3 calculates an integrated value of driving energy supplied to the first light emitting element 11 of the first light emitting unit 10 that does not include the KSF phosphor, and uses the calculated driving energy as the second light emission of the second light emitting unit 20. Supply to the element 21. Further, the control unit 3 calculates an integrated value of driving energy that can cancel the increase in emission intensity supplied to the second light emitting unit 20 side including the KSF phosphor, and corrects the calculated driving energy as a correction value. The amount of current is supplied to the second light emitting unit 20 side. Accordingly, the driving energy supplied to the second light emitting element 21 can be relatively reduced with respect to the driving energy input to the first light emitting element 11. As a result, the light output of the KSF phosphor when the emission intensity is dimmed by pulse width modulation can be maintained in the same spectral distribution as the light output of the KSF phosphor when DC driving is performed. Since the emission intensity ratio of the second light emitting unit 20 to the first light emitting unit 10 can be kept constant, it is possible to avoid a situation in which the emission color changes before and after the driving conditions, and high-quality illumination light can be obtained.

  The first light-emitting element 11 and the second light-emitting element 21 are blue light-emitting diodes that emit light in the same wavelength range. The blue light emitted by the first light-emitting element 11 and the second light-emitting element 21 causes green phosphor and red White light can be emitted by exciting the phosphor and mixing three colors of light. Further, as described above, in the case where the light emitting unit includes two or more packages, the packages can be appropriately combined to form a light emitting unit that maintains a balance of light emission colors. For example, two first light emitting units including a green phosphor and one second light emitting unit including a red phosphor may be combined. Furthermore, the illumination device of the present invention is not limited to illumination that emits white light, but may be an illumination device that outputs light of any color, or an illumination device that changes output light.

  The illumination device and the driving method thereof according to the present invention can be suitably used as a white illumination light source that suppresses a change in chromaticity due to a drive condition and particularly uses a blue light emitting diode as a light source. It can also be used for backlight light sources, LED displays, traffic lights, illumination switches, various sensors, various indicators, and the like.

DESCRIPTION OF SYMBOLS 100 ... Illuminating device 1, 1B, 1C, 1D, 1E ... Light emission part, 2 ... Power supply part, 3 ... Control part, 4 ... Memory | storage part 10, 10B, 10C ... 1st light emission part,
11, 11B, 11C, 11D, 11E ... First light emitting element, 12, 12B, 12C, 12D, 12E ... First phosphor, 13, 13B, 13C ... First package, 13D, 13E ... Common package, 14, 14B , 14C, 14D ... 1st recessed part, 14E ... Common recessed part, 16 ... Sealing member, 17 ... Lead electrode, 18 ... Lead electrode, 19 ... Conductive wire, 20, 20B, 20C ... 2nd light emission part, 21, 21B, 21C, 21D, 21E ... second light emitting element, 22, 22B, 22D, 22E ... second phosphor, 23, 23B, 23C ... second package, 24, 24B, 24C, 24D ... second recess, 25 ... 3rd fluorescent substance, 90 ... illuminating device, 91 ... light emitting element, 92 ... 1st fluorescent substance, 93 ... package, 94 ... recessed part, 95 ... 2nd fluorescent substance.

Claims (16)

A first light emitting element;
A first light emitting unit comprising a first phosphor that converts light emitted by the first light emitting element into light of a different wavelength;
A second light emitting unit comprising a second light emitting element;
A power supply unit that is electrically connected to the first light emitting unit and the second light emitting unit, respectively, and supplies a first driving energy to the first light emitting element and a second driving energy to the second light emitting element;
A control unit capable of individually controlling the first driving energy supplied from the power supply unit to the first light emitting unit and the second driving energy supplied from the power supply unit to the second light emitting unit;
With
The first light-emitting unit and the second light-emitting unit measure the light emission intensity of the first light-emitting unit and the second light-emitting unit while changing the driving conditions including the lighting time. When the emission intensity of the first light emitting part is normalized, the light emission intensity of the first light emitting part tends to increase as the driving time is shorter,
The control unit controls the integrated value of the first drive energy to be relatively lower than the integrated value of the second drive energy ,
The second light emitting unit includes a second phosphor that converts light emitted from the second light emitting element into light of a different wavelength,
Wherein the first phosphor, the second phosphor afterglow time is long red phosphor der Ru illumination device than body. A first light emitting element;
A first light emitting unit comprising a first phosphor that converts light emitted by the first light emitting element into light of a different wavelength;
A second light emitting unit comprising a second light emitting element;
A power supply unit that is electrically connected to the first light emitting unit and the second light emitting unit, respectively, and supplies a first driving energy to the first light emitting element and a second driving energy to the second light emitting element;
Control information for controlling the amount of the first drive energy and the second drive energy supplied by the power supply unit so as to be connected to the power supply unit and individually drive the first light emitting unit and the second light emitting unit, A control unit for sending to the power supply unit,
The control unit changes a light emission intensity ratio of the second light emitting unit to the first light emitting unit before and after the change of the driving condition when the driving condition including the lighting time of the first light emitting unit or the second light emitting unit is changed. The first driving energy or the second driving energy is controlled so as to keep constant ,
The second light emitting unit includes a second phosphor that converts light emitted from the second light emitting element into light of a different wavelength,
Wherein the first phosphor, the second phosphor afterglow time is long red phosphor der Ru illumination device than body. The lighting device according to claim 1 or 2,
The lighting device, wherein the driving condition is a duty ratio in a pulse width modulation method. It is an illuminating device as described in any one of Claims 1-3 ,
The second phosphor is an illumination device including an Eu-activated β sialon phosphor. It is an illuminating device as described in any one of Claims 1-4 , Comprising:
The first phosphor is
Composition formula _{3.5MgO · 0.5MgF 2 · GeO 2:} Mn is represented by Mn ^{4+ 4+} -activated Mg fluoro jar money preparative phosphor or composition formula ^{_{M 1 2 M 2 F 6:}} Mn 4+ ( However, M ^{1 is, Li +, Na +, K} +, Rb +, Cs +, at least one selected from NH ^4+, M ² is selected Si, Ge, Sn, Ti, from Zr A lighting device comprising a Mn ⁴⁺ activated fluoride phosphor represented by the formula: It is an illuminating device as described in any one of Claims 1-5 , Comprising: Furthermore,
The first light emitting unit and the second light emitting unit include a storage unit for storing a change amount of light emission intensity that changes according to a driving time,
Wherein the control unit refers to the SL 憶 portion such that said emission intensity of the first light emitting portion becomes constant, according to the drive time of the first light emitting portion or the second light emitting portion, a first drive energy The lighting device formed by adjusting the integrated value of the second or the integrated value of the second driving energy. It is an illuminating device as described in any one of Claims 1-6 ,
When the light emission intensity of the first light emitting unit increases as the driving time is shorter than that of the second light emitting unit, the control unit cancels the increase that is increased compared to the second light emitting unit. Thus, the illuminating device controlled so that the integrated value of said 1st drive energy supplied to said 1st light emission part may be reduced. It is an illuminating device as described in any one of Claims 1-6 ,
When the light emission intensity of the first light emitting unit increases as the driving time is shorter than that of the second light emitting unit, the control unit cancels the increase that is increased compared to the second light emitting unit. As described above, the lighting apparatus is configured to control to increase the integrated value of the second driving energy supplied to the second light emitting unit whose emission intensity is lower than that of the first light emitting unit. It is an illuminating device as described in any one of Claims 1-6 ,
The control unit drives the first light emitting element and the second light emitting element by a pulse width modulation method,
An illumination device in which a pulse width for driving the first light emitting element is controlled to be narrower than a pulse width for driving the second light emitting element. A lighting device according to any one of claims 1-9,
The second light emitting unit further includes, as a third phosphor, an illumination containing at least one of Eu-activated chlorosilicate phosphor, Eu-activated silicate phosphor, Eu-activated thiogallate phosphor, and rare earth aluminate phosphor apparatus. It is an illuminating device as described in any one of Claims 1-10 ,
The lighting device in which the first light emitting element and the second light emitting element are blue light emitting diodes. A lighting device according to any one of claims 1 to 11,
The first light emitting portion includes a first phosphor;
The lighting device in which the second light emitting unit includes the first phosphor in addition to the second phosphor. A lighting device according to any one of claims 1 to 12,
The lighting device in which the first light emitting unit and the second light emitting unit are formed in the same package. A lighting device according to any one of claims 1 to 13,
An illumination device in which the control unit has a dimming function for output light. A first light emitting element;
A first light emitting unit comprising: a first phosphor that converts light emitted by the first light emitting element into light of a different wavelength;
A second light emitting unit comprising a second light emitting element;
A power supply unit that is electrically connected to the first light emitting unit and the second light emitting unit, respectively, and supplies a first driving energy to the first light emitting element and a second driving energy to the second light emitting element;
A driving method of a lighting device, comprising: a control unit connected to the power source unit and controlling the control information for controlling the amount of the first driving energy and the second driving energy supplied by the power source unit to the power source unit Because
Causing the first light emitting unit and the second light emitting unit to emit light under different driving conditions, and measuring the light emission intensity under each driving condition;
Calculating a first drive energy or an integrated value of the second drive energy that keeps a constant light emission speed ratio of the second light-emitting part to the first light-emitting part for each of the driving conditions;
An integrated value of the first drive energy or the second drive energy the calculated, look including the step of supplying the first emitting section or the second light emitting portion,
The first phosphor is
Mn ⁴⁺ activated Mg fluorogermanate phosphor represented by a composition formula of 3.5MgO · 0.5MgF ₂ · GeO ₂ : Mn ⁴⁺ , or
The composition formula is M ¹ ₂ M ² F ₆ : Mn ⁴⁺ (where M ¹ is at least one selected from Li ⁺ , Na ⁺ , K ⁺ , Rb ⁺ , Cs ⁺ , NH ⁴⁺ , ^2, Si, Ge, Sn, Ti , at least one selected from Zr.) in Mn ⁴⁺ driving method of activated fluoride phosphors including lighting device represented. A first light emitting element;
A first light emitting unit comprising: a first phosphor that converts light emitted by the first light emitting element into light of a different wavelength;
A second light emitting unit comprising a second light emitting element;
A power supply unit that is electrically connected to the first light emitting unit and the second light emitting unit, respectively, and supplies a first driving energy to the first light emitting element and a second driving energy to the second light emitting element;
A control unit that is connected to the power source unit and controls the amount of the first drive energy and the second drive energy supplied by the power source unit to the power source unit;
The first light emitting unit and the second light emitting unit measure the light emission intensities of the first light emitting unit and the second light emitting unit while changing the driving conditions including the lighting time. When the light emission intensity of the first light emitting unit is standardized, the driving method of the lighting device showing a tendency to increase the light emission intensity of the first light emitting unit as the drive time is short,
Driving energy supplied to the first light emitting element so that the control unit cancels an increase in light emission intensity of the first light emitting unit as compared with the second light emitting unit as the driving time is shorter. Determining a correction amount for correcting the integrated value of
The control unit driving the second light emitting element with the second driving energy and driving the first light emitting element with the first driving energy corrected according to the determined correction amount;
Only including,
The first phosphor is
Mn ⁴⁺ activated Mg fluorogermanate phosphor represented by a composition formula of 3.5MgO · 0.5MgF ₂ · GeO ₂ : Mn ⁴⁺ , or
The composition formula is M ¹ ₂ M ² F ₆ : Mn ⁴⁺ (where M ¹ is at least one selected from Li ⁺ , Na ⁺ , K ⁺ , Rb ⁺ , Cs ⁺ , NH ⁴⁺ , ^2, Si, Ge, Sn, Ti , at least one selected from Zr.) in Mn ⁴⁺ driving method of activated fluoride phosphors including lighting device represented.

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